Papers used for ink-jet printing have typically included high-quality or wood-free papers designed to have high ink absorptivity. These papers are functionally good for ink-jet printing because the ink-jet inks may be absorbed readily and dry quickly. However, such papers often do not allow for a crisp or sharp image. Thus, in order to attain enhanced print quality and image quality as in a photograph, special media has been developed to work with aqueous inks. For example, various coated papers (art paper, coat paper, cast-coat paper, etc.) have been prepared by coating an ink-receiving layer on a paper substrate. Additionally, recording sheets have been prepared by coating an ink-receiving layer on paper or other supports, e.g., transparent or opaque plastic film supports. An example of such specialty media utilizes a micro-porous ink absorptive layer. Though micro-porous media provides a relatively good substrate with respect to certain image quality properties, one drawback that is encountered with the faster printing speeds are stacking defects, as a result of stacking more than one printed media before the ink has dried.
As digital imaging becomes more popular, and ink-jet output devices continue to push photo printing speeds, it has become increasingly important for ink-jet prints to be able to be stacked in printer output trays without causing color bleed (ink migration), color shifting, hazing (a reduction in the black optical density of a printed image), or sticking to adjacent media sheets, regardless of the type of coating used. In other words, as a byproduct of rapid printing speeds, printed media must often be stacked before the printed image is sufficiently dry to prevent ink migration, color shifting, or hazing. Though this problem is especially prevalent when using micro-porous media, it can be a problem with nearly all other types of media as well, depending on the ink, substrate, ink loading of the image, stacking time, and print speed selected for use.